The present invention relates to arc working torches of the kind comprising a removable cowling intended to surround the free extremity of the head of the torch. It is applicable more particularly although not exclusively to the manual plasma cutting torches in which the removable cowling helps protect the operator.
During utilisation of the torch, the electrode of a manual plasma cutting torch is raised to a comparatively high potential with respect to earth, of the order of 300 V. This electrode is normally rendered inaccessible by the presence of the nozzle of the torch, but the electrode is uncovered if disassembling of this nozzle is required for servicing the device, which is dangerous to the operator in case of accidental actuation of the control trigger of the torch.
For this reason, it has been proposed that the free end of the torch be provided with a removable protective cowling or hood whose presence prevents the disassembling of the nozzle. The fastening of this cowling on the torch body closes an electrical circuit which forms part of the torch safety circuit, which also comprises other circuits (for example corresponding to a correct supply of fluid). Nevertheless, the known systems did not yield complete satisfaction because they are comparatively difficult to produce and exhibit excessive cost.
It is an object of the invention to provide a removable cowling or hood, which is uncomplicated, may be handled reliabley and rapidly and is inexpensive.